Only just found the website but I thought I ould respond anyway.
Wragg orginally came from the name 'ragna'which is still a forename in Norway. The most pertinent to UK Wraggs is Lord Ragna, a Viking Lord who raped and pillaged his way down the East Riding of Yorkshire prior to the 11th century (making UK Wraggs indiginous inhabitants). Today the concentration is still within Yorkshire, Nottinghamshire & Derbyshire. On my own family tree I so far know that my direct ancestors were from Yorkshire, went to quell the Irish as soldiers but then settled and during the potato famine of the 1800's left to start a new life in America (there is a Wraggboro there) but my forebears never got further than Liverpool before settling in Wolverhampton. My parents moved to Sheffield where I was born.